refactor: Change SET LOCAL gucs to set_config

src/PostgREST/QueryBuilder.hs

@@ -16,8 +16,7 @@ module PostgREST.QueryBuilder (
   , readRequestToCountQuery
   , requestToCallProcQuery
   , limitedQuery
-  , setLocalQuery
-  , setLocalSearchPathQuery
+  , setConfigLocal
   ) where
 
 import qualified Data.ByteString.Char8           as BS
@@ -173,10 +172,7 @@ readRequestToCountQuery (Node (Select{from=qi, where_=logicForest}, _) _) =
 limitedQuery :: H.Snippet -> Maybe Integer -> H.Snippet
 limitedQuery query maxRows = query <> H.sql (maybe mempty (\x -> " LIMIT " <> BS.pack (show x)) maxRows)
 
-setLocalQuery :: Text -> (Text, Text) -> SqlQuery
-setLocalQuery prefix (k, v) =
-  "SET LOCAL " <> pgFmtIdent (prefix <> k) <> " = " <> pgFmtLit v <> ";"
-
-setLocalSearchPathQuery :: [Text] -> SqlQuery
-setLocalSearchPathQuery vals =
-  "SET LOCAL search_path = " <> BS.intercalate ", " (pgFmtLit <$> vals) <> ";"
+-- | Do a pg set_config(setting, value, true) call. This is equivalent to a SET LOCAL.
+setConfigLocal :: Text -> (Text, Text) -> Text
+setConfigLocal prefix (k, v) =
+  "set_config(" <> decodeUtf8 (pgFmtLit (prefix <> k)) <> ", " <> decodeUtf8 (pgFmtLit v) <> ", true)"